Why lead-acid batteries are used for cars as starting batteries, can we use lithium batteries?

Q: Can lead-acid batteries be replaced by lithium batteries for fuel vehicles to solve the problem of poor durability of starting battery?

Generally, after the flameout of the vehicle, the higher frequency of using the car, the higher frequency of replacing the battery. Therefore, people often ask: Can lithium batteries be used instead of lead-acid batteries for car starter batteries?

To say no, it would be too absolute. With the development and improvement of lithium battery production technology, more and more 12V batteries are now produced, that is, lithium batteries. However, some people may say that "lithium batteries are not safe". In recent years, there are often some safety accidents of lithium batteries, which push the safety performance of lithium batteries into the air of public opinion. But in fact, the real reason behind the lithium battery safety accident is the inferior modified lithium battery.

Here, I also remind my friends: To buy lithium batteries, we must buy them from regular sales places or lithium battery manufacturers with good reputation. At the same time, we must use the original charger to properly charge the battery, and do not illegally modify electric bicycles.

And as for whether we can use lithium batteries instead of lead-acid batteries as starter batteries for cars, this depends on the investment planning of car companies in design and manufacturing costs, as well as on their "environmental awareness" .

01. Analysis of cost variance

As the manufacturing cost of lead-acid batteries used to be the lowest, and the capacity standard of the "Q-type" (starting battery) for automobiles was relatively low, there are roughly the following three standards.

Low 12V-35Ah

Medium 12V-45Ah

 High 12V-65Ah

Perhaps this parameter standard will make many car enthusiasts feel incredible. Are there cars with 35Ah capacity batteries? The answer is yes, but it is more common in some well-known joint venture brand cars. If these batteries are mass-produced, the purchase cost of these batteries will be lower.

Are Lithium Batteries Really Expensive?

In fact, this view is also wrong, because there are many types of lithium batteries.

Lithium Titanate

Lithium cobaltate

Nickel Cobalt Aluminum

Nickel Cobalt Manganese

Lithium Iron Phosphate, etc.

The manufacturing cost of the first four kinds of lithium batteries is indeed very high, because titanium, cobalt and other elements are very expensive; and the price of cobalt is particularly unstable, because more than 60% of the production capacity is in the Congo,an unstable country. This small African country has recently experienced serious volcanic eruptions, the supply price of cobalt become even more difficult to control.Therefore, some suppliers or car companies are studying cobalt-free batteries, but the cost is still difficult to control, so such ternary lithium is not suitable for fuel vehicles.

Important: Lithium iron phosphate batteries can completely replace lead-acid batteries, because the manufacturing cost of this lithium battery is very low, its approximate standards are as follows.

3.2-3.7V 55Ah ≤120 CNY

3.2-3.7V 72Ah ≤150 CNY

3.2-3.7V 55Ah ≤120 CNY

3.2-3.7V 72Ah ≤150 CNY

The series connection of the batteries means "the capacity remains the same" and "the voltage increases", then as long as four iron-lithium batteries are connected in series, the voltage can meet the use of the car.

This is also the reason why national standard battery cars are upgrading lithium iron phosphate batteries. After all, the energy density of lithium iron phosphate batteries is several times that of lead-acid batteries, that is, the same battery life can be achieved with a smaller volume and lower weight, which is also a lightweight and fuel-saving way for cars. In two years, more vehicles are bound to start using this kind of battery.

02. What are the advantages and disadvantages of lithium iron phosphate starting batteries?

The disadvantage of lithium batteries used to be just high cost, but iron-lithium batteries avoid this perfectly.

The advantages of lithium iron phosphate batteries include:

High security

Long lasting

Light weight

Green and pollution-free

A high-standard lithium iron phosphate battery refers to a battery that has been subjected to a "needle short-circuit test" by at least two brands; that is, a steel needle penetrates the battery without catching fire or even generating high temperature. In terms of energy density, low-density lithium iron phosphate batteries are also higher than lead-acid batteries, while high-density lithium iron phosphate batteries have an energy density of 140WH/KG.

The service life of lead-acid batteries is very short, and they will be scrapped after being fully charged and discharged about 350 times; because each charge and discharge will cause the plate to vulcanize, and some of the multi-layer lead sulfate crystals that cannot be reduced will adhere to the plate, which has a negative impact on the activity of the battery. The efficiency of the material reaction can have a big impact. After severe vulcanization, it cannot be recharged, and the life of the battery will end.

Lithium iron phosphate batteries are generally considered to have "problems" after 1000-2000 times of complete charge and discharge, because electric vehicles will always come up with this data for analysis; but the real concept is that the capacity of the battery will drop by 20% to 30% after complete charge and discharge of about 2,000 times.

12.8V200Ah LiFePO4 Battery (Lead Battery Alternative) 

Therefore, as long as the car company has the technical planning of using lithium battery to replace lead-acid battery at the beginning of the vehicle design, the space layout of the vehicle engine compartment, the base design of the starting battery, the quality of the battery pack, etc., must be designed according to the parameter standard of lithium battery. Otherwise, it would not be easy to upgrade from the original lead-acid battery specifications to a lithium battery pack.